Identification of receptors for insect neuropeptides

1.家蚕细胞株BM-N4具有单一的家蚕毒素受体，其Kd=2.4 nM，每个细胞表面有16,000个结合位点。家蚕毒素受体由多个二硫键连接的亚基组成，结合亚基的相对分子质量约为105 kDa。此外，加入家蚕素后，约92 kDa的蛋白质在酪氨酸残基上立即被磷酸化。用聚合酶链式反应辅助的方法，对BM-N4细胞的BM-N4细胞的BM-N4受体基因进行了核苷酸序列分析。推导的氨基酸序列表明，家蚕毒素受体类似于胰岛素受体，由两个亚基组成。前胸腺只有一类PTTH受体，Kd=54 pm，每个细胞在细胞表面有16,000个结合位点。通过交联实验测得PTTH受体的相对分子质量约为75 kDa。

1. An Bombyx cell line, named BM-N4, has a single class of receptors for bombyxin with a Kd=2.4nM and each cell has 16,000 binding sites on the cell surface. The bombyxin receptor was composed of a several subunits linked with disulfide bonds and the molecular weight of binding subunit was about 105kDa. In addition, an about 92kDa protein was phosphorylated on tyrosine residue immediately after adding bombyxin.2. The nucleotide sequence of the cDNA for bombyxin receptor from BM-N4 cells was elucidated by using PCR assisted method. The deduced amino acid seqence revealed that bombyxin receptor is similar to insulin receptor and composed of two subunits.3. The prothoracic glands have a single class of receptors for PTTH with a Kd=54 pM and each cell has 16,000 binding sites on the cell surface. The molecular weight of PTTH receptor showed about 75kDa by cross-linking experiment.